21774769 has 2 divisors, whose sum is σ = 21774770. Its totient is φ = 21774768.

The previous prime is 21774763. The next prime is 21774787. The reversal of 21774769 is 96747712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21762225 + 12544 = 4665^2 + 112^2 .

It is a cyclic number.

It is not a de Polignac number, because 21774769 - 2¹⁵ = 21742001 is a prime.

It is a super-2 number, since 2×21774769² = 948281130006722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21774763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10887384 + 10887385.

It is an arithmetic number, because the mean of its divisors is an integer number (10887385).

Almost surely, 2^21774769 is an apocalyptic number.

It is an amenable number.

21774769 is a deficient number, since it is larger than the sum of its proper divisors (1).

21774769 is an equidigital number, since it uses as much as digits as its factorization.

21774769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 148176, while the sum is 43.

The square root of 21774769 is about 4666.3442864838. The cubic root of 21774769 is about 279.2444297909.

It can be divided in two parts, 2 and 1774769, that added together give a palindrome (1774771).

The spelling of 21774769 in words is "twenty-one million, seven hundred seventy-four thousand, seven hundred sixty-nine".